Hello, nice to be in this forum. I am not really new to Arduino but the last project I did dates a few years back. Right now I am building a hardware control for a raspberry pi running the OpenCPN navigation software. In the final project there are going to be around 15 hardware buttons that will control various ascpects of the software. My current idea is to somehow multiplex these buttons and then, using an Arduino type device send data to the Raspberry Pi either by USB or by I2C For USB I was thinking of an Adafruit Trinket. Can anyone here help me with the multiplexing of the hardware? I am not sure if there are enough pins on the arduino to achieve this.
Thanks for any suggestions!